Many diverse articles such as medical devices, orthotic devices, clothing and sports equipment, and furniture have incorporated elements which tend to conform to the shape of the user or some part of the user. Air splints are inflated to conform to the limb of an injured user, but are not intended to be reused in the conformed state. The splint is deflated and reinflated for reuse around another limb.
In U.S. Pat. No. 4,347,213 to Rogers, Jrs., cushions for chairs and other seats are made to conform to human body parts. In this device, a complex series of steps is required to conform the cushion to the contours of a particular body as follows. First, a sealed pliable bag filled with polystyrene pellets is placed in contact with the body and then a vacuum is applied to the bag to solidify the polystyrene mass. X-rays are used to confirm proper positioning. Next, plaster is applied to the external surface of the bag to form a shell, the bag and polystyrene are removed, and the shell serves as a mold for polyurethane which will serve as the cushion after it is covered. Alternatively, the polystyrene mass is smoothed with appropriate material, rigidified, and coated with a high friction surface.
Ski boot internal liners, such as disclosed in U.S. Pat. No. 4,083,127 to Hanson, and U.S. Pat. Nos. 4,144,658 and 4,255,202 to Swan, Jr. are further examples of products which conform to human body parts. These ski boot liners are flow pads which conform to the foot of a user. However, none of these liners are permanently formed to a specific foot by contacting the device with the foot. In these devices, the formable liner is designed to contour to the foot inside the boot at a particular time and to later resume the original uncontoured state when not in use.
Foot orthotics, such as disclosed in Ser. No. 93,408 filed Sept. 4, 1987 for "Orthotic Pads and Methods," assigned to the assignee of this invention, are molded to a specific foot and retain that shape permanently. However, as discussed in that patent, the use of a resin impregnated foam requires that a removable protective barrier be used between the actual orthotic device and the user's foot to prevent contact between the skin and the resin.
Known custom fit orthotic knee braces are deficient in that while substantially precisely fitting the leg of a particular user, they must be fitted using a series of steps and must be made in a shop. They can not be made in the presence of the potential user while the user waits. Custom fit braces typically require that a mold of the user's leg be made, and the mold serve as a form for a plaster of paris mixture which models the user's leg. The brace is then manufactured from the leg model. This process requires at least several days and can take several weeks between the initial fitting and the day the user takes home the brace. Additionally, the use of several steps to shape the brace reduces the precision of the brace. The resulting brace is not as precise as if it were shaped directly on the user's leg.